Add a pm8xxx-tm subdevice into pm8821-core. The pm8xxx-tm device can be used to receive an interrupt when critical temperature thresholds are reached. Since PM8821 does not have an ADC, it is not possible to read a real time PM8821 die temperature using this pm8xxx-tm device. Change-Id: I3720c79a0546e8bc69044166f70dd4c313e84daa Signed-off-by: David Collins <collinsd@codeaurora.org> (cherry picked from commit 1604779c47df4bf003211c35e356210e689676d5)